Electropneumatic brake



July 24, 1934 E, E EW TT 1,967,308

ELECTROPNEUMATIG BRAKE Filed Feb. 17, 1952 2 Sheets-Sheet l CABOOSE THI RD CAR SECOND CAR FIRST C R CATION APPu INVENTOR.

ELLIS E. HE WITT wyw A TTORNE Y.

LOCOMOTIVE July 24, 1934. HEW TT 1,967,308

' ELEGTROPNEUMATIC BRAKE Filed Feb. 17, 1952 2 Sheets-Sheet 2 SERVICE Fig.4

I RELEASET 8 I 1 RUNNNG '55 I so: I LE 4-! 5 53 6 65 74 I I I '1 42' INVENTOR ELLIS E. HEWITT A TTORNE Y.

Patented July 24, 1934 ,1

barren srnrns {PATENT QF F IG- E Q l I -iiesnaos V l ELEcTRorNEUMATIo BRAKE v Ellis E. Hewitt; Edgewood, Pa., assignor to The Westinghouse Air Brake Company, Wilin'er'ding, Pa., .a corporation of Pennsylvania li iieeaonnbi-uary '17, 1932, SerialNo. 593,582

6 Claims. (01. ?"s

This invention relates to railway brakes, and 17, a brake pipe 12, a feed valve device l6,';and more particularly to an electro-pneumatic brake a brake switch device 15 which is adapted to equipment. 1 be operated to effect electrical control :of the :In the processof installing electro pneumatic brakes. I

15 brake equipments. on railway cars, there will nec- The brake switch device 15 may comprisefixed "essarily be a transition period,in which some1cars terminal contacts 18, .19 and 20, and a movable are equipped with purely pneumatic brakeequipcontact drum 21 adapted to be moved into and merits and other cars with 'electro-pneumatic out 90f contact with the terminal contacts to tbrake equipments, so that trains will be made up control the electric operation of'the electro-pneu- $110 of 'cars having mixed equipments. 'It is, therematic brake apparatus in amanner to be here- 66 fore, highly desirable that means be provided inafter more specifically described. 7 p 'which will be eilec'tive to cause the brakes to A direct current generator 22, has oneterminal the applied and released on cars, whether equipped wire 28 connected to the switch contact 18, and with either electro-pneumatic or purely pneua plurality of train wires 23, 24 and,25,;which l 5 maticequipmentwires are connected respectively tortheswitch '70 One object of my invention is to provide a contacts 19 and 20 and to the other terminal of brake system in which the brakes can be applied the generator 22, through wire 29, will hereand released on all of the cars of the train, reinaiter be respectively referredto asapplication,

gardless of whether a car is equipped with an release and return wires, the train wires 23 and 220 electro-pneumatic or a purely pneumatic brake 24 being respectively connected to magnets 26 (5 equipment. 7 and 27 of the electro-pneumatic brake equip- A more specific object of my invention is to ment on the cars, which will be later described provide means whereby theloperation ofthe elecin detail. One terminal of each of the magnets tro-pneumatic brake equipment is effective to 26 and 2'? isconnected by a wire 32 to the return ,25 cause a reduction in brake pipe pressure, and wire 25. v H

thereby the operation of the purely pneumatic .The purely pneumatic equipment on each car brake on cars of the train so equipped. may, comprise a triple valve device 35, an auxiliary Another object of my invention is to provide reservoir. 36, anda brake cylinder 3'7. means for r nd rin h p ly pneumatic q p- In additionito the magnet devices 26 and 27,

1 merit inbp at v 011 Cars, q pped with an electhe electro-pneumatic brake apparatus includes tro-pneumatic brake apparatuawhen the electrovalve device =33 carried by a pipe bracket 39, pn um t brake apparatus i p ed'to effect which is secured between, the triple valve device anapplication of the brakes. 35 and the auxiliary reservoir 36.

Oth r Obj c s and advantages will appear in "The triple valve device on each-car. may be of 935 the following more detailed description of the th al type comprising a, casing having a 90 invention. v i chamber 40 connected directly to the brake-pipe In the acc p y dmWingSI F 1 is a through passage and pipe 41in the case oi cars diagrammatic View of a fiuid pressure brake sysequipped only ith a purely pneumatic brake "t m, dy -my nv i n, a d w s q pequipment, and to passage and pipe 41", con- ;40 mentfor a locomotive, three Cars and a (33330039, trolled by the valve device 38, in the case of cars 95 the equipment on the first two cars being of the equipped t t e1ectrO pneumafic-bmke appselectro-p eum'a p a d ear and ratus. Chamber 40 contains a piston 43 adapted caboose h g pu pneumatic t of l to operate a main slide valve 44 and a graduating ri 2 is a View, mainly in Section, Ofthe slide valve 45 contained in a chamber 46 con- 45 fiuidpress brake equipment the eleetrenected to the auxiliary reservoir 36. H 100 Pneumatie type; 3 VieW, mainly in The application. magnet valve device 26 may o of e fl d p e brake equipment of comprise a magnet 47 adapted to control oppopurely pneumatic type; e 4 is a develep- :sitely seating valves 48 and 49 containedinchamn V ew Of the brake Va v d v e Sh wn "on bers 50 and 5l respectively, thechambenfii) being '50 *the locomotive in Fig. -1, illustrating the connecconnected with the auxiliary reservoir 36thr0ugh 105 tioiis effected in its several operating positions. a passage 52 and the chamber 51 being'open -to The equipment shown in the accompanying the atmosphere throughpassage 53; "A coil spring drawings includes alocomotive brake equipment, 54, contained in the chamber 51," normally rewhich may comprise a main-reservoir 10, a" brake .tains the valve 49seated and *the valve 43 un- 55 valvedevice1l having the'usualoperating handle seated. A chamber 55, lying intermediate-the .3110

'usualmanner. brake pipe flows through pipe and passage 41 valves 48 and 49, is connected through a passage 56 to chamber '70 of an application valve device 57.

The release magnet valve device 2'7 may comprise a magnet 58 adapted to control oppositely seating valves 59 and 60 contained in chambers 61 and 62 respectively, the chamber 61 being open to the atmosphere through passage 63 and the chamber 62 being connected to the valve chamber 56 of the application magnet valve device 26 through a passage 64. contained in the chamber 62 normally retains the valve 60 seated and the valve 59 unseated. A chamber 66 lying intermediate the valves 59 and 60 is connected through a passage 67 to piston chamber '74'of the release valve device 38.

The application valve device 57 may comprise I ing from the inner seated area of the diaphragm valve is a passage 73 leading to the brake cylinder 3'7. 1

The release valve device 38 may comprise a casing having a piston chamber 74 connected to the passage 67 leading to the chamber 66 of the release magnet valve device 27. A chamber '74 contains a piston 75 adapted to operate a slide valve 76 contained in a chamber 77. A coil spring 78, contained Within the casing, serves to normally retain the slide valve 76 in its release position (as shown in Fig. 2 of the drawings). A

spring urged pin 79 acting upon the slide valve '76 serves as a resilient means to keep the valve seated.

Assuming that the locomotive, cars, and caboose are operatively connected as indicated diagrammatically in Fig. 1 of the drawings, the operator may manipulate the handle 17 of the brake valve device 11 and cause fluid under pres sure to be supplied to the brake pipe 12 in the The fluid thus supplied to the directly to the piston chamber of the triple valve devices on cars equipped only with purely pneumatic brake apparatus, and through pipe 42, cavity 80 in slide valve 76, and pipe 41 as well as through a branch pipe 42', past a check valve 81, and pipe 41' to the chamber 48 of the auxiliary reservoir 35 through the usual. feed groove 82, around the piston 48 and through the valve chamber 46. 7

On cars equipped with the electro-pneumatic brake apparatus, fluid under pressure supplied to the auxiliary reservoir 36 flows to both sides of the diaphragm 68 of the application valve device 57, to the lower face through passages 52 and 72 and to the chamber '78 at the upper face through passage 52, chamber 50, past the open valve 48, chamber .and passage 56.. Fluid under pressure also flows from chamber 50 of the application magnet valve device 26 to chamber 62 of therelease magnet valve device 27 through passage 64. With the triple valve device in release position, the brake cylinder passage '73, which leads from the inner seated area, of the A coil spring flexible diaphragm valve 68, is connected to the atmosphere through a cavity 83 in the main slide valve 44 of the triple valve device, passage 84, pipe 85, through cavity 86 in the slide valve 76, to release pipe 87 which may be provided with the usual retaining valve device 88. Since the inner seated area of the diaphragm 68 is thus connected to the atmosphere, as just described, the pressure of fluid in the chamber will maintain the diaphragm valve 68 seated on the seat rib 69 against the opposing pressure on the lower face of the diaphragm, so that there will be no loss of fluid past this valve from the auxiliary reservoir 36 to the atmosphere. The condition just described is made possible by the fact that the valve 59 of the release magnet valve device 27 is unseated so that piston chamber 74 is vented to exhaust port 63, and hence the coil spring 78 will cause the piston and slide valve 76 to be moved to the position shown in Fig. 2 of the drawings.

If it is desired to efifect an application of the brakes, with the equipment charged in the manner just described, through the medium of the electro-pneumatic brake apparatus, the brake valve device 11 should first be moved to lap position and then the brake switch is moved to application position, in which the switch drum 21 contacts with the contact terminals 18, 19 and 20, thus connecting one terminal of the direct current generator 22 to both the application train wire 23 and the release train wire 24. With these connections made, the magnet 47 of the application valve device 26, and the magnet 58 of the release valve device 2'7 are both energized and respectively effect the seating of valves 48 and 59. The seating of valves 48 and 59 respectively eliects the unseating of valves 49 and 60 against the respective pressures of coil springs 54 and 65. The seating of valve 48 cuts oir" communication between the auxiliary reservoir 36 and the chamber '70 of the application valve device 57 and by reason of the fact that the valve 49 is unseated, the chamber 70 is vented to the atmosphere through passage 56, chamber 55, past the valve 49 and passage 53. With the chamber '70 thus vented, fluid under pressure from the auxiliary reservoir 36, acting on the under face of the diaphragm 68, causes the same to be flexed upwardly to un seat it from the seat ring 69 and permits fluid from the auxiliary reservoir to flow through passage 73 to the brake cylinder 37. With the valve 60 unseated in the manner previously described, fiuid under pressure flows from the auxiliary reservoir 86 through passage 52, chamber 50, passage 64, past the valve 60, through chamber 66 and passage 67 to the piston chamber 74 of the release valve device 38. Fluid from the auxiliary reservoir, thus supplied to the piston chamber '74, causes the piston '75 to be moved to the right against the pressure of the spring 78 to cause the slide valve 76 to be shifted into lap position, wherein communication between pipes and 87 vby way of the cavity 86 in the slide valve 76 is cut off, so that the release of fluid fromthe brake cylinder is prevented.

In order to limit the degree of brake cylinder pressure in effecting an application of the brakes, the operator, after moving the brake switch device 15 to application position in the manner previously described, moves the brake switch device to lap position, as soon as the desired brake cylinder pressure has been obtained. In lap position, the electrical circuit through the magnet 47 of the application magnet valve device 26 is opened,

while maintaining the magnet 58 of the release steam magn t? valved'evice fil energised; 'deeu'er gizationfof the magnet 4*7' 'pe'r-inits me valve- 49 t'o be seated under the acti'ori "of thecoil spring and at the same time the was 49wi1lbun seated: In'tliis mariner, cbmniunmaaaabecween the chamber and the atmosphere is cut rease the chamber 70 is "placed in open commuiiicatlbn withthe auxiliary "reservoir 36, so that theichaniber '7fl' again becomes'charg'ed with fluid under auxiliary reservoir pressure," which causes the diaphragm 6S to be aske downwardly into-'seat"- ing engagement with the" seat ring 69' to out of! further supply of fliiid froni tlie" auxiliary "reset voir 3'6" to'tli'e brake cylinder? To effect an 5 electric release of thebrakes; the operator moves the brake switch device- 15': to release "position; thus opening the magnetcircuits through hoth the application magnet valve "device ZF- a'nd the're'leas'e mag'n'et valve device 27 which resume in the-deenergization offlth 'e magnets 47 and'ts'. With the magnet's'i l and 58"- oi each electro=pneumatic brake apparatus deeneng'ized; the diaphragm 68of 'th'e application valve device 57 will-bese'ated to' cutoff the flowof'fiuidunder pressure from the 'auxiliary resen'voir'36 to'l the brake cylinder 37 in themannehpreviouslv des'cribedi Withthe magnet 58" of eachelectropneumaticbrake apparatus 13 deenergized, the spring65 will move the valve 60to' its seat and the valve 59 willbe unseatedi The seating of the valve 60 cutsoihcommunica'tion betweenthe chambers 62 and" 66" and thus cuts off the supply of fluid from the auxiliary'reservoir" tdthe piston chamber 74 of the frel'ease valve device 38. The unseating of the valve 59 establishescommunication between chambers 66and 61: and thus per rnitsthe venting offluid urider pressure from 'the pi'stdn chamber '74 to the atmosphere through assage 67, chamber 66; past valve: 59,,through chamber 61 and assage 63; When the piston chamber 74- is vented to 'the -atinosphere; the coil spring 'wmoves the pis'tbn 75 and slide valve '76 to the left to establish 'aiconnection between pipesSS and 87 through the cavity 86 formed in the slide valve '76. With this ccnnection'established fluid under pressure is exhausted from the brake cylinder through passage '73, cavity 83 in the main slide valve 4401? the triple valve device 35, passage 84, pipe 85, cavity 86, and release pipe 87 to effect a release of the brakes.

When an electric application of the brakes is efiected in the manner previously described it will result in the automatic operation of the purely pneumatic triple valve devices on cars equipped only with pneumatic brake apparatus. This will be accomplished due to the reduction in brake pipe pressure resulting from the electric operation of the electro-pneumatic brake apparatus.

When an electro-pneumatic brake application is effected, the auxiliary reservoir pressure is reduced by flow to the brake cylinder, and the triple valve piston 43 on cars equipped with the electropneumatic brake apparatus, remaining in release position fluid will flow from the piston chamber 40 through the feed groove 82 to the valve cham ber 46 and the auxiliary reservoir, and consequently fluid under pressure will be vented from the brake pipe 12 by flow through the pipe 42, pipe 42, past the check valve 81 and through pipe 41 to piston chamber 40.

The reduction in brake pipe pressure thus produced on cars equipped withthe electro-pneumatic brake apparatus, will be sufficient to cause the operation of the triple valve devices on cars equipped only withpneumatic brake apparatus,

so as tb 'efiect pneumatic appilcation or the brakes on cars so equipped. v

It willvbenbtd that neither the triple valve piston" 4ll nor the slide valves-4A and 451 oi the triple valvedevices oncars equipped with the nears-pneumatic brake apparatus, are moved upon an electr c-pneumatic application of the brakes: v q

Th is due not onl'y to the fact that'the auxili'aiy reservoir"pressureiis being 'redu'ced 'oh the valv ch'amber side of the triple valve pistbn= 48; but alsobecause; the release slide valve" 76is move-d m an=elctro -pneuniatic'br-ake application; so as to cut" oil communication from pipe 1 1" t'd -pipe 42' and the Brake pipe 12, and sinc'e fluid c'anndt 'b'e vented from the piston' chamber- 4i) by way of the bypass pipe 42', byreason of the checli valve 81, it will beis'eerr that any reduction in brake pipe pressure, due to leakage oiflotherw-i'se, will not be transmitted t6 the piston 'chamberlO l V If, for any reason, such as-failure'or inopera tiveiiess-of 'tlie eIect'rO pneumatic brake apparawa it is desired to efiect an application of the brakes pneumatically, this-may be dbne'by-moV- ing theb'rake valve handle 17 of the brake valve device "11- to service application position, in which a reduction in" brake pipe pressure is effected in the mus-1' well known manner.

wrap the brake pipe pressure is thus reduced and the electro-pneumatic brake apparatus 'remainsinactive, the triple valve devices on cars equippedwith-"the electrmpneumatio brake ap at-rams as Well' as the triple valve devices on cars equipped only" with pneumatic brake" apparatus; areoperatedin the usual manner toeffect'art'ap'plication of the" brakes In this case, a reduction in fluid pressure in the'pist'on chambe'riill ofi the triplevalve'devices on cars equipped with the elective-pneumatic brake apparatus, is efiectedthr'ough pipe 4 1 cavity sum-ale release slide valve" 76} and=pipe 421' romm-e foregoing, it will be evidentthat-with my revenues; when some carsof the train are equipped with an electro-pneumatic brake apparatus, and other cars only with a purely pneumatic brake apparatus, the brakes may be applied and released on all the cars of the train when an electro-pneumatic brake application is effected. Furthermore, it will be seen that means have been provided to prevent the pneumatic operation of the electro-pneumatic brake apparatus upon a reduction in brake pipe pressure resulting from leakage or from the electric operation of said apparatus.

While the invention has been described in considerable detail in the foregoing specification, it is understood that various changes may be made in its embodiment without departing from or sacrificing any of the advantages hereinafter claimed.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The combination with a brake pipe, an auxiliary reservoir, a brake cylinder, and a brake controlling valve device operated upon a reduction in brake pipe pressure for supplying fluid from the auxiliary reservoir to the brake cylinder, of an electro-pneumatic brake apparatus operative electrically to supply fluid from the auxiliary reservoir to the brake cylinder, means controlling a communication from said brake controlling valve device to the brake pipe and operative upon operation of said electro-pneul ft) matic brake apparatus to apply the brakes, to cut ofl said communication. v ,2. The combination with a brake pipe, an auxiliary reservoir, a brake cylinder, and a brake controlling valve device operated upon a reduction in, brake pipe pressure for supplying fluid from the auxiliary reservoir to the brake cylinder, of an electro-pneumatic brake apparatus operative electrically to supply fluid from, the auxiliary reservoir to the brake cylinder, a fluid pressure operated valve device controlling a communicationthrough which fluid is vented from said brake controlling valve device to the brake pipe, and a magnet valve device operated to.supply fluid under pressure to operate said valve device to cut off said communication concurrently with the operation of said electro-pneurnatic brake apparatus to supply fluid from the auxiliary reservoir to the brake cylinder.

3. The combination with a brake pipe, an auxiliary reservoir, a brake cylinder, and a triple valve device operated upon a reduction in brake pipe pressure for supplying fluid from the auxiliary reservoir to the brake cylinder, of a mag net valve device operated electrically to supply fluid fromthe auxiliary reservoir to thebrake cylinder, a valve mechanism controlling communication through which fluid is vented from said triple valve device to the brake pipe, and a magnet valve device operated electrically for effecting the operation of said valve mechanism to cut ofi said communication concurrently with the operation of said first mentioned magnet valve device to supply fluid from the auxiliary reservoir to the brake cylinder. I

4. The combination with a brake pipe, an auxiliary reservoir, a brake cylinder, and a triple valve device operated upon a reduction in brake pipe pressure for supplying fluid from the auxiliary reservoir to the brake cylinder, of; a magnet valve device operated electrically to supply fluid from the auxiliary reservoir to the brake, cylinder, a valve mechanism controlling a communication through which fluid is vented from said triple valve device to the brake pipe and another com munication through which fluid is vented from the brake cylinder, and a magnet valve device operated electrically for eflecting the operation of said valve mechanism to close said communications.

5. The combinat on with a brake pipe, an auxiliary reservoir, a brake cylinder, and a triple valve device having a piston subject to the opposing pressures of the brake pipe and auxiliary reservoir and operated upon a reduction in brake pipepressurefor supplying fluid from the auxiliaryreservoir to the brake cylinder, there being a communication through which fluid may be supplied from the brake pipe to said piston and a communication through which fluid may be vented from said piston to the brake pipe, of a valve mechanism controlling the communication through which fluid is vented from said piston to the brake pipe, and electrically controlled means for effecting the operation of said valve mechanism to close the communication controlled by said valve mechanism.

6. The combination with a brake pipe, an auxiliary reservoir, a brake cylinder, and a triple valve device having a piston subject to the opposing pressures of the brake pipe and auxiliary reservoir and operated upon a reduction in brake pipe pressure for supplying fluid from the auxiliary reservoir to the brake cylinder, said piston controlling a communication through which fluid is supplied from the brake pipe to the auxiliary reservoir, of an eleetro-pneumatic brake apparatus operated electrically for supplying fluid from the auxiliary reservoir to the brake cylinder, whereby the brake piper pressure is reduced by flow from the brake pipe through said communication to the auxiliary reservoir, and a valve mechanismoperated upon operation of said electro-pneumatic brake apparatus to supply fluid to the brake cylinder for cutting off a communication through which fluid is vented from said piston to the brake pipe.

. ELLIS E. HEWITT. 

